1. Field of the Invention
The present invention relates to interfaces, communication apparatuses, and programs.
2. Description of the Related Art
With the advancement of processors, communication terminals, as exemplified by cellular phones, are approaching the same level of functionality as personal computers. In particular, communication terminals that have GUIs (Graphical User Interfaces) are capable of providing interfaces to users to suit various purposes. For this reason, in addition to telephones, there are high expectations for the use of such interfaces in near-field communication compliant with the NFC (Near Field Communication) standard.
To carry out near-field communication, it has thus far been necessary to bring an antenna disposed on a rear surface side of a communication terminal close to an external device serving as the subject for communication. A mark is therefore provided on the rear surface of the communication terminal to indicate the antenna position.
However, if, for example, the communication terminal is equipped with a cover or the like made of silicon rubber, the mark indicating the antenna position can no longer be seen from the exterior. Meanwhile, in the case where the housing of the communication terminal is made of a metal such as aluminum or stainless steel, problems such as a decrease in the communication range and an inability to communicate altogether can arise. Furthermore, when using a comparatively large communication terminal such as a tablet terminal or the like to read out information recorded in a smartcard, it is more convenient to be able to carry out the near-field communication from the front surface side of the communication terminal.
A technique for implementing near-field communication from the front surface side of a communication terminal has been proposed (see Japanese Unexamined Patent Application Publication No. 2006-195802, for example). A reader/writer apparatus disclosed in Japanese Unexamined Patent Application Publication No. 2006-195802 includes an antenna that is overlapped with a liquid crystal panel display screen. This enables favorable communication with devices, smartcards, and so on positioned on the front surface side of the liquid crystal panel.
An antenna pattern in the reader/writer apparatus disclosed in Japanese Unexamined Patent Application Publication No. 2006-195802 is formed by sputtering a transparent conductive material on a transparent substrate that overlaps with the liquid crystal panel and then patterning the sputtered material. There is thus a problem in that the structure of the display device that includes the antenna pattern is complicated. Specifically, the position of the antenna pattern relative to the liquid crystal panel will differ depending on the model of the reader/writer apparatus, its applications, and so on. It is therefore necessary to form different antenna patterns for each model.
ITO (Indium Tin Oxide) is often used as the stated transparent conductive material. However, ITO has less than or equal to 1/100 the conductivity of such highly-conductive metals as copper, aluminum, or silver. Antennas having coils configured of ITO thus have difficulty achieving Q characteristics that provide satisfactory antenna performance.
Furthermore, in the case where a shield plate is disposed on the rear surface of the liquid crystal panel to block noise emanating from the liquid crystal panel, induced current produced by the shield plate can lead to a worsening of the antenna characteristics.